Liquid crystal display device

Abstract

To prevent a phenomenon that an alignment film material is difficult to flow into the through-hole where a diameter of a through-hole for connecting between a pixel electrode and a source electrode is reduced. A liquid crystal display device comprising a TFT substrate having pixels each including a common electrode formed on an organic passivation film, an interlayer insulating film formed so as to cover the common electrode, a pixel electrode having a slit and formed on the interlayer insulating film, a through-hole formed in the organic passivation film and the interlayer insulating film, and a source electrode electrically conducted to the pixel electrode via the through-hole. A taper angle at a depth of D/2 of the through-hole is equal to or more than 50 degrees. The pixel electrode covers part of a side wall of the through-hole but does not cover the remaining part of the side wall of the through-hole. This configuration facilitates the alignment film material to flow into the through-hole, thereby solving a thickness unevenness of the alignment film in vicinity of the through-hole.

What is claimed is: 
     
       1. A liquid crystal display device comprising:
 a TFT substrate having pixels each including
 a common electrode formed on an organic passivation film, 
 an interlayer insulating film formed so as to cover the common electrode, 
 a pixel electrode formed on the interlayer insulating film, the pixel electrode having a slit, 
 a through-hole formed in the organic passivation film and the interlayer insulating film, and 
 a source electrode electrically conducted to the pixel electrode via the through-hole; 
 
 a counter substrate having a black matrix formed thereon; and 
 liquid crystal sandwiched between the TFT substrate and the counter substrate, 
 wherein, where the through-hole formed in the organic passivation film assumes a cross-section in which a top face is defined on the side of the counter substrate and a bottom face is defined on the side of the source electrode, the top face having a diameter larger than that of the bottom face, the through-hole having a depth of D,
 a taper angle at a depth of D/2 of the through-hole is equal to or more than 50 degrees, and 
 
 wherein the pixel electrode covers part of a side wall of the through-hole but does not cover the remaining part of the side wall of the through-hole. 
 
     
     
       2. A liquid crystal display device according to  claim 1 , wherein the taper angle of the through-hole is equal to or more than 60 degrees. 
     
     
       3. A liquid crystal display device comprising:
 a TFT substrate having pixels each including
 a pixel electrode formed on an organic passivation film, 
 a through-hole formed in the organic passivation film, 
 a source electrode electrically conducted to the pixel electrode via the through-hole, 
 an interlayer insulating film formed so as to cover the pixel electrode, and 
 a common electrode formed on the interlayer insulating film, the common electrode having a slit; 
 
 a counter substrate having a black matrix formed thereon; and 
 liquid crystal sandwiched between the TFT substrate and the counter substrate, 
 wherein, where the through-hole formed in the organic passivation film assumes a cross-section in which a top face is defined on the side of the counter substrate and a bottom face is defined on the side of the source electrode, the top face having a diameter larger than that of the bottom face, the through-hole having a depth of D,
 a taper angle at a depth of D/2 of the through-hole is equal to or more than 50 degrees, and 
 
 wherein the common electrode covers part of a side wall of the through-hole but does not cover the remaining part of the side wall of the through-hole. 
 
     
     
       4. A liquid crystal display device according to  claim 3 , wherein the taper angle of the through-hole is equal to or more than 60 degrees. 
     
     
       5. A liquid crystal display device comprising:
 a TFT substrate having pixels each including
 a common electrode formed on an organic passivation film, 
 an interlayer insulating film formed so as to cover the common electrode, 
 a pixel electrode formed on the interlayer insulating film, the pixel electrode having a slit, 
 a through-hole formed in the organic passivation film and the interlayer insulating film, and 
 a source electrode electrically conducted to the pixel electrode via the through-hole; 
 
 a counter substrate having a black matrix formed thereon; and 
 liquid crystal sandwiched between the TFT substrate and the counter substrate, 
 wherein, where the through-hole formed in the organic passivation film assumes a cross-section in which a top face is defined on the side of the counter substrate and a bottom face is defined on the side of the source electrode, the top face having a diameter larger than that of the bottom face, the through-hole having a depth of D,
 a taper angle at a depth of D/2 of the through-hole is equal to or more than 50 degrees, and 
 the slit of the pixel electrode extends to a depth of 1 μm or more from a top surface of the organic passivation film or to a depth of D/4 or more from the top surface of the organic passivation film. 
 
 
     
     
       6. A liquid crystal display device according to  claim 5 , wherein the slit extends to the bottom face of the through-hole. 
     
     
       7. A liquid crystal display device according to  claim 6 , wherein the taper angle of the through-hole is equal to or more than 60 degrees. 
     
     
       8. A liquid crystal display device according to  claim 5 , wherein the taper angle of the through-hole is equal to or more than 60 degrees. 
     
     
       9. A liquid crystal display device comprising:
 a TFT substrate having pixels each including
 a pixel electrode formed on an organic passivation film, 
 a through-hole formed in the organic passivation film, 
 a source electrode electrically conducted to the pixel electrode via the through-hole, 
 an interlayer insulating film formed so as to cover the pixel electrode, and 
 a common electrode formed on the interlayer insulating film, the common electrode having a slit; 
 
 a counter substrate having a black matrix formed thereon; and 
 liquid crystal sandwiched between the TFT substrate and the counter substrate, 
 wherein, where the through-hole formed in the organic passivation film assumes a cross-section in which a top face is defined on the side of the counter substrate and a bottom face is defined on the side of the source electrode, the top face having a diameter larger than that of the bottom face, the through-hole having a depth of D,
 a taper angle at a depth of D/2 of the through-hole is equal to or more than 50 degrees, and 
 the slit of the pixel electrode extends to a depth of 1 μm or more from a top surface of the organic passivation film or to a depth of D/4 or more from the top surface of the organic passivation film. 
 
 
     
     
       10. A liquid crystal display device according to  claim 9 , wherein the slit extends to the bottom face of the through-hole. 
     
     
       11. A liquid crystal display device according to  claim 10 , wherein the taper angle of the through-hole is equal to or more than 60 degrees. 
     
     
       12. A liquid crystal display device according to  claim 9 , wherein the taper angle of the through-hole is equal to or more than 60 degrees.